Method and device for removing a bone from an extremity of a slaughter animal

ABSTRACT

In a method and device, an elongate bone is removed from a meat-comprising extremity or part thereof of a slaughter animal. The bone has a first joint end, which forms part of a first joint, and a second joint end, which forms part of a second joint. The bone is taken out of the extremity at the first joint end, a tissue connection between the extremity and the second joint end of the bone substantially being retained. Then, meat is moved away from the bone in the region of the second joint end of the bone as a result of at least a part of the bone being moved in its longitudinal direction with respect to a scraper device towards and in particular beyond the second joint end, and the tissue connection between the extremity and the bone is mechanically broken.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is the U.S. national phase of International ApplicationNo. PCT/NL02/00696 filed on Nov. 1, 2002 and published in English asInternational Publication No. WO 03/039262 A2on May 15, 2003, whichapplication claims priority to Netherlands Application No. 1019293 filedon Nov. 5, 2001, the contents of which are incorporated by referenceherein.

The invention relates to a method for removing an elongate bone from ameat-comprising extremity or part thereof of a slaughter animal, inparticular an extremity of a bird, such as a chicken, turkey, duck orthe like, which bone has two opposite joint ends, which in the natural,e.g. unprocessed, state of the slaughter animal each form part of adifferent joint between the bone and another part of the slaughteranimal, which method comprises the step of taking the bone out of theextremity at a first of the joint ends thereof, with a tissue connectionbetween the extremity and the second joint end of the bone substantiallybeing retained. The invention also relates to an assembly for carryingout the method. In the context of the invention, an extremity isunderstood as meaning a limb, i.e. a leg or a wing, the bone in questionbeing a femur or a humerus. The extremity or a part thereof may beconnected to the body of the slaughter animal before undergoing a boningoperation according to the invention, but it is also possible for theextremity or part thereof to have been separated from the body prior tothe boning operation.

A method of this type and an assembly of this type for boning a leg ofpoultry are known, for example, from U.S. Pat. No. 5,176,562. To preparefor the boning, a longitudinal cut is made manually along the thighboneand the drumstick bone, on the inner side of the leg, i.e. the sidewhich faces the associated other leg in the natural position.Furthermore, a transverse cut is made manually at the knee joint, inorder to partially sever connective tissue in that area, i.e. tendonsand connecting muscles. Then, other tendons and connecting muscles aremechanically severed at the knee joint, and the thighbone ismechanically moved out of the thigh meat at the end facing the kneejoint via the longitudinal cut which has been made, after which that endof the thighbone which faces the hip joint may still be connected to thethigh meat by means of connective tissue. The thighbone is laterdetached from the thigh meat if this has not already taken place. Afteran incision has been made at the tarsal joint, the drumstick meat isscraped off the drumstick of the leg in the direction of the knee jointthereof.

WO-A-00/59311 describes a boning operation in which a poultry leg issuspended by its tarsal joint. Suitable knives are used to automaticallyand mechanically make longitudinal cuts along the thighbone and thedrumstick bone and also the transverse cut in the region of the kneejoint. That section of the thighbone which adjoins the knee joint isthen pressed out of the thigh meat, in the transverse direction withrespect to the leg, by means of an arm. A guide presses the thighbonefurther out of the thigh meat, the thighbone remaining connected, at ahip joint end thereof, to the thigh meat and therefore to the extremity.Finally, the bone is separated from the extremity.

EP-A-0 763 326 describes a similar operation, in which the thighbone ismanually cut out of the thigh meat.

The known method and device have the drawback that the thighbone is notmechanically removed from the leg with any degree of reliability. Thisrequires manual inspection and further processing.

It is an object of the invention to provide a method and device in whicha bone, such as a thighbone or a wingbone, is mechanically separatedfrom an extremity, such as a leg or a wing, as part of a boningoperation which can be carried out either in completely mechanised formor at most partially by hand.

Another object of the invention is to provide a boning operation inwhich an optimum quantity of meat is obtained, i.e. there is a minimalquantity of meat lost during the boning.

To achieve at least one of the above objects, the method according tothe invention is characterized by the steps of moving the bone and themeat away from one another in the region of the second joint end of thebone; and breaking the tissue

connection between the extremity and the bone. In this way, the bone andthe meat connected thereto are moved with respect to one another tovarious spatial locations, the bone and the meat being connected to oneanother only by means of connective tissue. This tissue connection canthen be broken very effectively, with a minimal remainder of the tissueconnection remaining on the second joint end of the bone.

As an optional preliminary processing operation on the extremity, alongitudinal cut can be made in the extremity, which longitudinal cutextends at least between the first and second joint ends of the bone,and a transverse cut can be made in the extremity at the first joint endin order to at least partially sever tissue connections in the vicinityof the first joint.

It is preferable for at least a section of the bone to be moved in itslongitudinal direction with respect to a scraper device, towards thesecond joint end, in order to move the meat away from the bone in theregion of the second joint end of the bone, in particular to beyond thesecond joint end. The bone may be stationary with respect to a point inspace and the scraper device can move with respect to the said point,but it is also possible for the bone to be moved with respect to astationary scraper device. It is also possible for both the bone and thescraper device to move with respect to a fixed point in space. Only thefact that the scraper device and the bone move relative to one anotheris of importance.

It is preferable for the tissue connection between the extremity and thebone to be broken by being cut through at the location of the scraperdevice, or by being pulled off. The first option has the advantage thatthe position where the tissue is broken is accurately determined, whilethe second option has the advantage of simplicity.

To achieve at least one of the above mentioned objects, an assemblyaccording to the invention for removing an elongate bone from anextremity of a slaughter animal, which bone has two opposite joint endswhich in the natural, for example unprocessed state of the slaughteranimal each form part of a different joint between the bone and anotherpart of the slaughter animal, comprises: means for taking the bone outof the extremity at a first of its joint ends, a tissue connectionbetween the extremity and the second joint end of the bone substantiallybeing retained, and the assembly is characterized by: means for movingthe bone and the meat away from one another in the region of the secondjoint end of the bone; and separation means for breaking the tissueconnection between the extremity and the bone.

The means for moving the bone and the meat away from one another in theregion of the second joint end of the bone preferably comprise a scraperdevice which is adapted to scrape along the bone towards the secondjoint end of the bone, in particular to beyond the second joint end.

In the method and device according to the invention, a knife whichextends substantially in a plane and has a first side and a second side,and is provided with a first cutting surface, which extends on the firstside of the knife, at an angle of 8 –15°, in particular at an angle of10 –11°, with respect to the plane of the knife, is preferably used tobreak connective tissue. To increase the effectiveness of the knife, itis possible to provide a second cutting surface, which extends on thefirst side of the knife, at an angle of 20 –40°, in particular an angleof 27 –33°, with respect to the plane of the knife. To further increasethe effectiveness, the knife may be provided with a third cuttingsurface, which extends on the second side of the knife, at an angle of10 –20°, in particular at an angle of 15°, with respect to the plane ofthe knife.

It is preferable for the knife to be circular and for it to be providedwith at least one radial, in particular elongate recess along acircumferential edge thereof. The recess preferably is substantiallyU-shaped or V-shaped.

It is preferable for at least the cutting surface to be provided with alayer of TiN or CrN.

The knives according to the invention are highly effective, have a longservice life and have a very favorable service life/cost ratio, whilethe level of staining during use is acceptable.

Other claims, features and advantages of the invention will become clearwith reference to the appended drawing, which shows non-limitingexemplary embodiments and in which:

FIG. 1 shows a perspective view of a thighbone removal device;

FIGS. 2 a, 2 b and 2 c respectively show a perspective front view, aside view and a perspective rear view of a thighbone removal componentof the thighbone removal device shown in FIG. 1;

FIGS. 3 a and 3 b show perspective views of the transfer of thethighbone to the thighbone removal component of FIGS. 2 a–2 c;

FIG. 3 c shows a side view of the way in which the thighbone is cut offa limb;

FIG. 4 a shows a perspective view of a variant of the thighbone removaldevice shown in FIG. 1;

FIG. 4 b shows a perspective view of a variant of the thighbone removaldevice shown in FIG. 4 a;

FIG. 4 c shows a perspective view of another variant of the thighboneremoval device shown in FIG. 1;

FIG. 5 shows a perspective view of an alternative thighbone removaldevice;

FIG. 5 a shows a perspective view of yet another thighbone removaldevice;

FIG. 6 shows a perspective view of a wingbone removal device, in whichthe wingbone is handled in a first way;

FIG. 7 a shows a perspective view of a wingbone removal device, in whichthe wingbone is handled in a second way;

FIGS. 7 b and 7 c show a detailed view of the way in which the wingboneis handled in accordance with FIG. 7 a;

FIG. 8 shows a perspective view of an alternative wingbone removaldevice;

FIGS. 9 a, 9 b and 9 c respectively show a front view, a side view and adetailed view in cross section of a rotatable knife in a firstembodiment;

FIGS. 10 a, 10 b and 10 c respectively show a front view, a crosssection and a detail in cross section of a rotatable knife in a secondembodiment;

FIGS. 11 a, 11 b and 11 c respectively show a front view, a crosssection and a detail in cross section of a rotatable knife in a thirdembodiment; and

FIGS. 12 a, 12 b and 12 c respectively show a front view, a crosssection and a detail in cross section of a rotatable knife in a fourthembodiment.

Throughout the various figures, identical reference numerals denoteidentical components or components with an identical function.

FIG. 1 shows a conveyor 2 with rails 4 along which hooks 6, which areknown per se, are advanced in the direction of arrow 8 in a manner whichis not shown in more detail but is known per se, for example by a drivenchain to which each hook 6 is connected. Each hook 6 is adapted tosupport two legs 10 of a slaughter animal at the tarsal joint thereof.It should be noted that it is also possible to use hooks which areadapted to support one leg or more than two legs.

Beneath the conveyor 2 a conveyor 12 is situated, in which chains 16,which are driven by sprocket wheels 14, are used to advance thighboneremoval components 18 in the direction indicated by arrow 20. When thethighbone removal components 18 are moving along a rail 22 of theconveyor 12, they are moving substantially parallel to and synchronouslywith the hooks 6.

Finally, a rotatable knife 23, which is driven via a spindle 25 in amanner which is not shown in more detail, is arranged in a fixedposition with respect to the conveyor 12.

The thighbone removal components 18 which are shown in FIGS. 1 and 2 a–2c each comprise a body 24 which is provided with claws 25 which areadapted to engage around the rail 22. A base plate 26 is fixedly securedto the body 24 and a control plate 28 can move with respect to the baseplate, in the directions indicated by double arrow 30. The control plate28 is provided with a cam or freely rotatable wheel 32 which, byinteracting with a suitable guide 34 which is positioned next to thepath of the thighbone removal component 18, is responsible for providingthe desired displacement of the control plate 28 with respect to thebase plate 26. Two arms 40, which can pivot about a pin 36 in thedirections indicated by double arrow 38, are arranged on the base plate26. Each arm 40 has a substantially semicircular recess 42 which isassociated with a substantially semicircular recess 44 of the base plate26 in order to form a scraper opening 46. A spring 48, which actsbetween the base plate 26 and each arm 40 and at its ends is connectedto said respective components, ensures that each arm 40 is forcedtowards the base plate 26 in order to form a closed scraper opening 46.By contrast, a downward displacement of the control plate 28 withrespect to the base plate 26 ensures that the arms 40 pivot counter tothe biasing force of the spring 48 in order to move the recesses 42 and44 away from one another for opening the scraper opening 46.

On the body 24 there is a pin 50 which bears arms 52 provided withrecesses 51 and is pivotable in the directions indicated by double arrow54. The pin 50 is connected, in the body 24, to a pin 56, which projectsthrough a slot in the base plate 26 and bears a roll 58 at one end. Anupward or downward movement of the roll 58, for example as a result ofthe roll being guided in a groove 60 (FIG. 1) of a guide 62 which isarranged in a fixed position along the path of the thighbone removalcomponent 18, leads to pivoting of the pin 50 and consequently tomovement of the recesses 51 away or towards the scraper opening 46,respectively.

The device shown in FIG. 1 operates as follows. Legs 10 are supplied onthe left-hand side of the figure in the conveyor 2 in the directionindicated by the arrow 8. The hooks 6 from which the legs 10 aresuspended move synchronously with the thighbone removal components 18,each leg 10 moving at the location of a scraper opening 46 of one of thethighbone removal components 18. Before the legs 10 reach the conveyor12 or while the legs 10 are moving over the conveyor 12, the thighboneis partially detached from each leg 10 by detaching the tendonconnections at the knee joint and tilting the thighbone downwards aboutthe connection between the thighbone and the leg, which is still atleast partially intact, at the location of the hip joint. The scraperopening 46 is opened as a result of the arms 40 being pivoted away fromthe base plate 26 through the wheel 32 being moved downwards withrespect to the base plate 26. As an alternative, the wheel 32 can bemoved downwards with respect to the base plate 26 to such an extent thatthe spring force of spring 48 is substantially overcome but the scraperopening 46 remains closed; the arm 40 can then be pivoted with respectto the base plate 26 using very little force. As illustrated at 70 and72, each thighbone which has been partially detached is on the one handplaced in the recesses 42 and 44 between an arm 40 and the correspondingpart of the base plate 26, and on the other hand is placed in the recess51 in the arm 52. The scraper opening 46 is then closed again, c.q. thecomplete spring force of the spring 48 is restored by releasing thewheel 32.

The dimensions of the recess 51 are such that one end of the thighbone,at the knee joint side thereof, cannot pass through the recess 51. Thedimensions of the scraper opening 46 are substantially such that thethighbone can pass through it, including the end of the thighbone on thehip joint side, the spring 48 ensuring that the scraper opening 46 canwiden if necessary in order to allow the latter end of the thighbonepass. The oyster connected to the thighbone cannot pass the scraperopening 46. At 74 it is illustrated that next moving the arms 52 awayfrom the scraper opening 46 leads to the thighbones being displacedthrough the scraper openings 46 in the longitudinal direction thereof,the ends of the thighbones ultimately passing the scraper opening 46 onthe hip joint side and being located on that side of the arms 40 whichfaces the arms 52. In fact, the arms 52 move so far away from the baseplate 26 that even a thighbone with the maximum possible length willreliably pass the scraper opening 46. Then, the arms 52 are moved in theopposite direction over a distance which is such that the ends of thethighbones, irrespective of the length thereof, come to bear against thebase plate on the hip joint side as a result of the tension in thetissue connections of the thighbones to the remainder of the legs. Inthis state, the thighbone removal component 18 moves past the knife 23and the thighbone is cut off the thigh meat.

FIGS. 3 a and 3 b illustrate a way in which a thighbone can be partiallydetached from a leg 10 by hand and can be positioned in the thighboneremoval component 18 (corresponding to FIG. 1) at 72. As a preliminaryprocessing operation, a longitudinal cut has already been made along theentire length of the leg 10 on that side of the leg 10 which in thenatural position faces the other leg. The preliminary processingoperation has also seen a transverse cut made at the knee joint. Thistransverse cut has only a limited depth, in order to ensure that thekneecap remains connected to the drumstick bone when the drumstick isremoved in a later stage. As shown in particular in FIG. 3 a, after thepreliminary processing operation the end of the thighbone on the kneejoint side thereof is cut off with the aid of a wizard knife 80 (anendless knife in band form which is driven in its longitudinal directionwith respect to a handle) handled by a person and is taken hold of. Thethighbone is then pulled out of the leg 10 on the knee joint side, thethighbone tilting about the still partially intact connection betweenthe thighbone on the hip joint side and the thigh meat. Then, thethighbone, as illustrated in FIG. 3 b, is placed into the recess 51 andthe scraper opening 46 with the aid of the wizard knife 80. This isfollowed by the processing as illustrated in FIG. 1 at 74.

FIG. 3 c illustrates in particular the processing which is carried outby the knife 23 (FIG. 1), starting from the positioning of a thighbone82 which is reached at 74 in FIG. 1. The base plate 26 moves past theknife 23 at a very short distance and in the process cuts in the regionof the scraper opening 46 on the side of the base plate 46 which facesthe arms 52. However, it is also possible, as indicated by dashed linesin the Figure, for the knife to be arranged in such a manner that itcuts in the area of the scraper opening 46 on the opposite side of thebase plate 26. The result of the cutting operation by the knife 23 isthat the thighbone 82 is separated from the leg 10. Parallel to the pathof the thighbone removal component 18 there may be a guide 83 whichpresses the thighbone 82 downwards in order to improve the positioningof that end of the thighbone 82 which rests against the base plate 26.This prevents this thighbone end, which is rounded in shape, fromprojecting into the scraper opening 46, so that the knife 23 does notcut into the end of the thighbone. The guide 23 furthermore ensures thatloosely hanging pieces of meat are kept away from the knife 23.

The thighbone 82 which has remained in the thighbone removal component18 is then disposed of in a suitable way, so that the thighbone removalcomponent 18 is ready for its next use.

The device shown in FIG. 4 a substantially corresponds to the deviceshown in FIG. 1. For the sake of clarity, the guide 62 has been omittedfrom the Figure. One difference with respect to FIG. 1 lies in theaddition of movable brackets 200 in the device shown in FIG. 4 a, whichbrackets 200 are designed to move synchronously with the displacement ofthe legs 10 and are also designed to move transversely with respect tothe direction of the arrow 8, in the directions indicated by doublearrow 201, between a first position outside the path of the legs 10(shown by dashed lines) and a second position in the path of the legs10. The way in which the brackets 200 are driven is not shown in moredetail and can easily be implemented by a person skilled in the art. Thebrackets 200 push the legs 10 towards the associated thighbone removalcomponent 18, so that the manual operation of gripping the thighbone andpulling it out of the thigh meat, which operation has been described indetail above with reference to FIGS. 3 a and 3 b, can be carried outmore easily and more quickly, since the brackets 200 position andsupport the legs 10. Instead of a bracket 200, it is also possible touse any other moving or stationary support member to fulfill a similarfunction. The device shown in FIG. 4 b substantially corresponds to thatshown in FIG. 4 a. One difference lies in the addition of at least onemechanical arm 202 with a number of degrees of freedom of movement. Thearm 202 is driven in a suitable way, for example with the aid ofelectric, pneumatic and/or hydraulic motors. At its free end, the arm202 is provided with a wizard knife 80 and is furthermore controlled insuch a manner that substantially the same function of gripping athighbone and removing it from the thigh meat can be performed as hasbeen explained for a manual treatment with reference to FIGS. 3 a and 3b. For this purpose, by way of example, sensors (not shown in moredetail) are provided which control the position of the wizard knife 80with respect to the relevant thighbone and the associated thighboneremoval component 18, so that a thighbone is moved into the scraperopening 46 and the recess 51 in the desired way. The use of the brackets200 in combination with the arm 202 is useful but not necessary; the arm202 can be used even if the brackets 200 are not present.

The device shown in FIG. 4 c substantially corresponds to that shown inFIG. 1. One functional difference is the automatic operation of thedevice shown in FIG. 4 c. One structural difference in this respectcomprises the addition of guides 84 for laterally supporting legs 10moving past. Furthermore, a guide 86 is provided which is arrangedopposite the guides 84. The guides 84, 86 are connected to a frame in asuitable manner (not shown in more detail). The guide 86, which isdirected obliquely downwards, is provided, at its upstream end, with anejector element 88. While the legs are being conveyed along the guides84, 86, the ejector element 88 moves into the legs behind thethighbones. Then, the thighbones are tilted out of the legs along theguide 86 and positioned in the recesses 51 and the scraper openings 46,after which the processing operations which have already been describedwith reference to FIG. 1, for further removal of the thighbones from thelegs 10, take place.

FIG. 5 shows an alternative device for the removal of thighbones fromlegs 10. Beneath the conveyor 2 there are two sets of rolls 100, 101which can rotate about their longitudinal axis and are driven in amanner which is not shown in more detail. The rolls 100 rotate inopposite directions 104, as do the rolls 101, which rotate in oppositedirections 106. The rolls 100, 101 are provided with projections 108,preferably made from a flexible material. In addition, at least one rollof each set of rolls may be provided with means for conveying legs 10which are in contact with the rolls in the longitudinal direction of therolls 100, 101. Each set of rolls 100, 101 delimits a gap to which aguide 110 leads. Above the rolls 100, 101 there are knives 112 and 114,respectively, which are adapted to be active above the gap of theassociated set of rolls. The knives 112, 114 are driven in rotation byrespective motors 116, 118 via respective transmissions 120, 122.

The device shown in FIG. 5 operates as follows. Moving from the left tothe right in the Figure, in the direction indicated by the arrow 8 oftransport of the legs 10, first of all the thighbones are at leastpartially detached from the thigh meat with the aid of a manualoperation using a wizard knife 80 (cf. FIG. 3 a). Obviously, it is alsopossible for this operation to be performed at the desired position in amanner which has been described with reference to earlier FIGS. Then,the thighs of the legs 10 are guided via the guide 110 to the gapsbetween the rolls 100 and 101, respectively. In each gap, the thigh meatis engaged by the projections 108 on the rolls 100, 101 and pushedupwards through the gap between the rolls 100, 101. The thighbonescannot pass through the gap between the rolls 100 and 101, with theresult that the remaining connections between the thighbones and thethigh meat are placed under prestress, and in some cases are broken.Connections which are not broken as a result of the action of theprojections 108 are severed by the knives 112, 114. In both cases, thetissue connections between the thighbones and the remainder of the legsare ultimately broken, and the thighbones are discharged onwards, forexample via a chute 121. The legs, from which the thighbones have beenremoved, then continue on their way in the conveyor 2.

The above-described action of each set of rolls 100, 101 can also beobtained in a device in which one of the rolls is smooth or is replacedby a static guide which extends parallel to the other roll. Anembodiment of this type is shown in FIG. 5 a. Beneath the conveyor 2there is a set of rolls 210, 212 which can rotate about theirlongitudinal axes and are driven in a manner which is not shown in moredetail. The rolls 210, 212 rotate in mutually opposite directions 214.The roll 210 is provided with longitudinal ribs 216 or some other typeof profiling, preferably made of a flexible material. The roll 212 has asubstantially flat surface. The longitudinal ribs 216 or other profilesmay also be arranged on roll 212 instead of on roll 210, or both on roll210 and on roll 212. At least one of the rolls 210, 212 may be providedwith means for conveying legs 10 which are in contact with the rolls210, 212 in the longitudinal direction of the rolls 210, 212. The set ofrolls 210, 212 delimits a gap with a width which is such that athighbone cannot pass through the gap. At the downstream end of the gap(as seen in the direction of the arrow 8) a knife 218 is arranged. Inthe embodiment shown, the knife is in disc form and is driven by a motor220, but it is also possible for the knife to be static. Below the knife218 there is a chute 222.

The device shown in FIG. 5 a operates as follows. Starting from the leftand moving towards the right as seen in the Figure, in the direction ofarrow 8 of transport of the legs 10, firstly the thighbones are at leastpartially detached from the thigh meat with the aid of a manualprocessing operation using a wizard knife 80 (cf. FIG. 3 a). Obviously,it is also possible to carry out this operation in a manner which hasbeen described with reference to previous figures. If necessary, thelegs 10 are rotated about a vertical axis in such a manner that thethighbones are on the front side of the legs 10, as seen in thedirection of transport. The rolls 210, 212 are arranged in the path ofthe legs 10 in such a manner that the thighbones of the legs 10 end upbeneath the gap between the rolls 210, 212. They are then unable to passthrough the gap, despite the direction of rotation 214 of the rolls 210,212. The rotation of the rolls 210, 212 causes any thigh meat which issituated in the gap to be moved upwards out of the gap, so that thisthigh meat comes to rest substantially on the rolls. The knife 218 whichis located downstream of the rolls then breaks the connection whichstill exists at the location of the hip joint end between the thighboneand the thigh meat, after which the thighbone is discharged via thechute 222 and the leg 10 continues onward in the direction indicated byarrow 8.

FIG. 6 illustrates the removal of the humerus from wings of slaughteredpoultry using substantially the same device as that which has alreadybeen discussed with reference to FIGS. 1, 2 a–2 c, 3 a–3 c and 4 a forremoval of the femur. Since the dimensions of the humerus and the femurdiffer, the dimensions and movement distances of the active componentsof the device shown in FIG. 6 may differ from those used in the previousdevices, but their basic operation remains the same.

The device shown in FIG. 6 operates as follows. Carcasses 230 of poultryare supplied by conveyor 2 in the direction indicated by arrow 8, asindicated on the left-hand side of the Figure. In a preceding processingstep, the shoulder joints of the carcasses 230 have at least in partbeen subjected to incisions, preferably substantially on the hip side ofthe location where the wing 232 is joined to the body 234. The shoulderjoint may have been dislocated, and the incision may extend into orthrough the joint. A tissue connection between the wing 232 and the body234 is retained. Furthermore, the elbow joint has been severed in aprevious processing step.

As shown for the carcass 230 a, the body 234 of the carcass 230 a hasbeen displaced in the direction of a wingbone removal component 236 bythe bracket 200, the shoulder joint end of each humerus being cut out(if necessary) with the aid of a wizard knife 80 and the humerus beingtaken hold of and placed into the opened scraper opening 46 and therecess 51 (FIG. 2 c) of the associated wingbone removal component 236.Then, the scraper opening 46 is closed, as indicated at carcass 230 b.The shoulder joint end of the humerus cannot pass the recess 51, so thatthe humerus is pulled out of the wing meat when the arm 52 is tilted(indicated at carcass 230 c), and this wing meat is retained by the baseplate 26. The wings 232, from which the humerus has been removed in thisway, remain connected to the body 234 of the carcass 230 via a tissueconnection.

The device shown in FIG. 7 a substantially corresponds to the deviceshown in FIG. 6. The way in which the humerus is removed differs,however. As shown in detail in FIG. 7 b for the carcass 230 d in FIG. 7a, in an initial processing step a longitudinal incision has been madein the wing 232 along the humerus, and the elbow joint has beendislocated or severed. The shoulder joint may optionally have undergonea prior processing operation, such as an incision or a dislocation. Asillustrated in FIG. 7 c for the carcass 230 e in FIG. 7 a, the wizardknife 80 is used to take hold of the elbow joint end of the humerus andtake it out of the wing 232, after which the removal of the humeruswhich has been described above with reference to FIG. 6 takes place.However, according to FIG. 6, the shoulder joint end of the humerusrests against the arm 52, while according to FIG. 7 a the elbow jointend of the humerus rests against the arm 52.

It will be clear that manual gripping of the humerus, as shown in FIGS.6, 7 a and 7 c, can also be carried out using a mechanical arm as shownin FIG. 4 b.

In accordance with the description given above in connection with thewings, it is also possible for a thighbone to be removed from a leg ifthe leg is still connected to the carcass, by making an incision at thehip joint, and if appropriate also at the knee joint, and then grippingthe hip joint end of the thighbone and removing the thighbone using athighbone removal device as described above. It is also possible, afteran incision has been made at the knee joint, and if appropriate also atthe hip joint, for the knee joint end of the thighbone to be gripped inorder for the thighbone then to be removed.

FIG. 8 shows how carcasses 230 are conveyed in the direction indicatedby arrow 8, with the back of the carcasses facing in the direction oftransport. It is also possible for the abdomen of the carcasses to facein the direction of travel. It is possible to use a conveyor 2 (FIG. 1).Beneath the conveyor 2 and parallel to the direction of transport thereare two humerus positioning elements 240 which can rotate about theirlongitudinal axis and are driven, in a manner not shown in more detail,to rotate in opposite directions 242. The humerus positioning elements240 are provided with flaps 244 which extend in the longitudinaldirection and are preferably made from a flexible and/or resilientmaterial, and a gap is defined between the humerus positioning elements240, substantially having the same width as the body 234 of the carcass.Downstream of the humerus positioning elements 240 there are guides 246,mounted in a frame which is not shown in more detail. In the wingboneremoval components 236 a shown in FIG. 8, the active assemblies of arms40, 52 and base plate 26 are positioned next to one another (as seen inthe direction of arrow 8) instead of one behind the other, as is thecase, for example, in FIG. 6. The basic method of operation is otherwiseidentical and is as follows.

Carcasses 230 are supplied, a preliminary processing operation as shownin FIG. 7 b having taken place. Then, the body 234 of each carcass 230is moved into the gap between the humerus positioning elements 240, theflaps 244 taking the humerus out of the wing 232 on both sides of thebody 234. In the process, the humerus moves upwards and may possiblyalready be partially in the recess 51 and the open scraper opening 46.After it has left the gap, each humerus moves under an associated guide246, by means of which the humerus is moved fully into the recess 51 andopened scraper opening 46 of the wingbone removal component 236 asconveying of the carcass 230 continues. Then, the humerus is pulled outof the wing in the manner which has already been explained above withreference to FIGS. 6 and 7 a.

The knives shown in the devices illustrated in FIGS. 1, 4 a, 4 b, 4 c, 5and 5 a may be designed as described below.

FIGS. 9 a, 9 b and 9 c show a knife 160, in particular a circular knife,with holes 161 and 162 for securing the knife 160 with the aid of screwsor the like, for example, to a drive structure (not shown in moredetail), such as a spindle and/or a flange, for rotating the knife 160about a central axis of rotation which is perpendicular to the plane ofthe knife 160. An annular first region or cutting surface 163 along thecircumferential edge of the knife 160 is ground at an angle α of 8–15°,in particular 11°, with respect to the plane of the knife 160, and anannular second region or cutting surface 164 along the circumferentialedge of the knife 160 is ground at an angle β of 30–40°, in particular32.5°, with respect to the plane of the knife 160. The grinding patternis shown at 165. The knife 160, in particular the cutting surfaces 163,164, is provided with a titanium nitride (TiN) or chromium nitride (CrN)coating. If the entire knife 160 is provided with the coating, thecoating only disappears on one side of the knife 160 when the knife 160is reground after use. The knife 160 is used to make incisions in partsof slaughter animals, in particular to cut off a hip bone of a leg of aslaughter animal or to cut breast pieces, stomachs, thigh skin or neckskin of poultry.

FIGS. 10 a, 10 b and 10 c show a knife 170, in particular a circularknife, with a hole 171 for securing the knife 170 with the aid of screwsor the like, for example, to a drive structure (not shown in moredetail), such as a spindle and/or a flange, for rotating the knife 170about a central axis of rotation perpendicular to the plane of the knife170. An annular first region or cutting surface 172 along thecircumferential edge of the knife 170 and on the front side thereof isground at an angle α of 8 –15°, in particular 10°, with respect to theplane of the knife 170, and an annular second region or cutting surface173 along the circumferential edge of the knife 170 and on the rear sidethereof is ground at an angle β of 10–20°, in particular 15°, withrespect to the plane of the knife 170. The grinding pattern is indicatedat 174. Four elongate radial recesses 175, which in particular have alength which is greater than the width of the area 172, are arrangedalong the circumferential edge of the knife 170. If necessary, there maybe more or fewer recesses 175, distributed evenly or unevenly along thecircumference as required, and having an identical or different lengthor width as required. The knife 170, in particular the cutting surfaces172, 173, is provided with a titanium nitride (TiN) or chromium nitride(CrN) coating. The knife 170 is used to make incisions in parts ofslaughter animals, in particular to cut off a hip bone of a leg of aslaughter animal or to cut thigh skin of poultry.

FIGS. 11 a, 11 b and 11 c show a knife 180, in particular a circularknife, having a hole 181 for securing the knife 180 with the aid ofscrews or the like, for example, to a drive structure (not shown in moredetail), such as a spindle and/or a flange, for rotating the knife 180about a central axis of rotation perpendicular to the plane of the knife180. An annular first region or cutting surface 182 along thecircumferential edge of the knife 180 and on the front side thereof isground at an angle α of 8–15°, in particular 10°, with respect to theplane of the knife 180, and an annular second region or cutting surface183 along the circumferential edge of the knife 180 and the rear sidethereof is ground at an angle β of 10–20°, in particular 15°, withrespect to the plane of the knife 180. The grinding pattern is indicatedat 184. Four elongate, substantially V-shaped radial recesses 185, whichin particular have a length which is substantially equal to the width ofthe area 182, are arranged along the circumferential edge of the knife180. That end of each recess which faces towards the axis of rotation ofthe knife 180 is ground at an angle γ of 20–35°, in particular 27°, withrespect to the plane of the knife 180. If necessary, there may be moreor fewer recesses 185, which may be distributed evenly or unevenly alongthe circumference as required and may be of identical or differentlength as required, and may have the same or a different angle betweenthe opposite sides of the recesses as required. The knife 180, inparticular the cutting surfaces 182, 183, is provided with a titaniumnitride (TiN) or chromium nitride (CrN) coating. The knife 180 is usedto make incisions in parts of slaughter animals, in particular to cutoff a hip bone of a leg of a slaughter animal or to cut wings or filletsof poultry.

FIGS. 12 a, 12 b and 12 c show a knife 190, in particular asubstantially circular knife, having holes 191 and 192 for securing theknife 190 with the aid of screws or the like, for example, to a drivestructure (not shown in more detail), such as a spindle and/or a flange,in order to rotate the knife 190 about a central axis of rotationperpendicular to the plane of the knife 190. An annular first region orcutting surface 193 along the circumferential edge of the knife 190 andon the front side thereof is ground at an angle α of 8–15°, inparticular 10°, with respect to the plane of the knife 190, and anannular second region or cutting surface 194 along the circumferentialedge of the knife 190 and on the rear side thereof is ground at an angleβ of 20–35°, in particular 27.5°, with respect to the plane of the knife190. The grinding pattern is indicated at 195. Twenty-four elongate,substantially U-shaped radial recesses 196, which in particular have alength which is less than the width of the region 193, are arrangedalong the circumferential edge of the knife 190. That end of each recesswhich faces towards the axis of rotation of the knife 190 is ground atan angle γ of 20–35°, in particular 27°, with respect to the plane ofthe knife 190. If necessary, there may be more or fewer recesses 196,distributed evenly or unevenly along the circumference as required, andhaving an identical or different length as required. The knife 190, inparticular the cutting surfaces 193, 194, is provided with a titaniumnitride (TiN) or chromium nitride (CrN) coating. The knife 190 is usedto make incisions in parts of slaughter animals, in particular forcutting off a hip bone of a leg of a slaughter animal or for cuttingstomachs or legs of poultry.

The invention has been illustrated above with reference to legs forremoval of the thighbone therefrom and with reference to wings forremoval of the humerus therefrom. It is not necessary for theextremities to be separated from the body of the slaughter animal inquestion prior to the bone removal: if the body joint is dislocatedprior to the bone removal and surrounding tissue connections have beenat least partially broken, the bone removal may also take place whilethe extremity is still connected to the body of the slaughter animal.

1. A method for removing an elongate bone from an extremity or partthereof of a slaughter animal by an assembly configured for removing theelongate bone, the elongate bone having a longitudinal axis and firstand second joint ends, the extremity or part thereof comprising meat andthe method comprising: a. removing the first joint end of the bone fromthe extremity with a bone removal device, wherein a tissue connectionbetween the extremity and the second joint end of the bone issubstantially retained; b. moving at least one of the bone and the meataway from the other in the region of the second joint end with a movingdevice; and c. breaking the tissue connection between the extremity andthe second joint end of the bone with a separating device.
 2. The methodof claim 1, wherein moving at least one of the bone and the meat awayfrom the other comprises moving the bone relative to a scraper device ina direction substantially parallel to the longitudinal axis of the boneso that the scraper device scrapes the bone from a position between thefirst and the second joint ends and moves relative to the bone in thedirection of the second joint end.
 3. The method of claim 2, wherein thescraper device moves relative to the bone to a location beyond thesecond joint end of the bone.
 4. The method of claim 2, wherein breakingthe tissue connection between the extremity and the bone comprisescuffing the at least one tissue connection proximal the scraper device.5. The method of claim 1, wherein the slaughter animal, when intact,comprises a body and a body joint between the bone and the body, whereinthe body joint comprises the second joint end.
 6. The method of claim 1,wherein breaking tissue connection between the extremity and the bonecomprises ripping the at least tissue connection.
 7. The method of claim1, wherein the first joint end forms a first joint with at least a firstjoint end of a second bone, the method further comprising the step ofmoving the first joint end of the bone away from the first joint end ofthe second bone with the bone removal device.
 8. The method of claim 7,wherein the slaughter animal, when intact, comprises a body and a bodyjoint between the bone and the body, wherein the body joint comprisesthe first joint end.
 9. An assembly for removing an elongate bone,having a longitudinal axis and first and second joint ends, from anextremity or part thereof of a slaughter animal, the extremity or partthereof comprising meat and the assembly comprising: a. a bone removaldevice for removing the first joint end of the bone from the extremity,a tissue connection between the extremity and the second joint end ofthe bone being substantially retained; b. a moving device for moving atleast one of the bone and the meat away from the other in the region ofthe second joint end; and c. a separating device for breaking the tissueconnection between the extremity and the second joint end of the bone.10. The assembly of claim 9, wherein the moving device comprises ascraper device adapted to engage the bone and scrape along the bonetoward the second joint end of the bone.
 11. The assembly of claim 10,wherein the moving device further comprises an arm adapted to engage thebone in the vicinity of the first joint end and to displace the bonerelative to the scraper device engaging the bone.
 12. The assembly ofclaim 10, wherein the separating device comprises a blade positionedadjacent the scraper device.
 13. The assembly of claim 9, wherein theslaughter animal, when intact, comprises a body and a body joint betweenthe bone and the body, wherein the body joint comprises the second jointend.
 14. The assembly of claim 13, wherein the moving device comprises ascraper device adapted to engage the bone and scrape along the bonetoward the second joint end of the bone.
 15. The assembly of claim 14,wherein the moving device further comprises an arm adapted to engage thebone in the vicinity of the first joint end and to displace the bonerelative to the scraper device engaging the bone.
 16. The assembly ofclaim 9, wherein the moving device comprises two parallel rolls.
 17. Theassembly of claim 16, wherein the distance between the rolls is smallerthan the transverse dimensions of the bone.
 18. The assembly of claim16, wherein an outer surface of at least one roll comprises projections.19. The assembly of claim 18, wherein the projections comprise ribs. 20.The assembly of claim 9, wherein the moving device comprises a roll anda guide which is parallel to the roll.
 21. The assembly of claim 20,wherein the distance between the roll and the guide is smaller than thetransverse dimensions of the bone.
 22. The assembly of claim 9, whereinthe bone removal device comprises a knife.
 23. The assembly of claim 9,wherein the bone removal device comprises two parallel rolls.
 24. Theassembly of claim 23, wherein the rolls comprise projections.
 25. Theassembly of claim 24, wherein the projections comprise flaps.
 26. Theassembly of claim 9, wherein the first joint end forms a first jointwith at least a first joint end of a second bone, and the bone removaldevice moves the first joint end of the bone away from the first jointend of the second bone.
 27. The assembly of claim 26, wherein theslaughter animal, when intact, comprises a body and a body joint betweenthe bone and the body, wherein the body joint comprises the first jointend.